forms.py

from django import forms
from django.contrib.auth.models import User
from yourapp.models import Profile

class SignUpForm(forms.ModelForm):
    username = forms.CharField(
        required=True,
        widget=forms.TextInput()
    )
    email = forms.EmailField(
        required=True,
        widget=forms.EmailInput()
    )
    password = forms.CharField(
        widget=forms.PasswordInput()
    )
    password2 = forms.CharField(
        label=_("Password Confirmation"),
        widget=forms.PasswordInput()
    )
    error_message = {
        'password_mismatch': _("The two password didn't match."),
    }
    
    class Meta:
        model = Profile
        fields = '__all__'
        exclude = ['user',]

    def clean_password2(self):
        password1 = self.cleaned_data.get('password')
        password2 = self.cleaned_data.get('password2')
        if password1 and password2 and password1 != password2:
            raise forms.ValidationError(
                self.error_message['password_mismatch'],
                code='password_mismatch',
            )
        return password2
    
    def save(self, commit=True):
        user = super(SignUpForm, self).save(commit=False)
        user_registration = User.objects.create_user(
            username=self.cleaned_data['username'],
            password=self.cleaned_data['password'],
            email=self.cleaned_data['email']
        )
        if commit:
            user_registration.save()
        return user_registration

models.py

from django.db import models
from django.contrib.auth.models import User


class Profile(models.Model):
  user = models.ForeignKey(
     User, related_name='user_profile'
  )
  avatar = models.ImageField(
     upload_to='uploads/avatar/%Y/%m/%d',
     null=True, blank=True
  )
  about = models.TextField(
     null=True, blank=True
  )
  
  def __str__(self):
     return self.user.username

register.html

{% extends "base.html" %}

{% block content %}
  <form action="." method="POST" enctype="multipart/form-data">
    {% csrf_token %}
    {{ form.as_p }}
    <button type="submit">Register Now</button>
  </form>
{% endblock %}

views.py

from django.shortcuts import (render, redirect)
from django.contrib.auth import (authenticate, login, logout)

from yourapp.models import Profile
from yourapp.forms import SignUpForm

def register(request):
    if request.method == 'POST':
        form = SignUpForm(request.POST, request.FILES, instance=Profile())
        if form.is_valid():
            cd = form.cleaned_data
            username = cd['username']
            password = cd['password']
            
            user = authenticate(username=username, password=password)
            initial = form.save(commit=False)
            initial.user = user
            initial.save()
            form.save()
            
            if user is not None and user.is_active:
                login(request, user)
                return redirect('/')
    else:
        form = SignUpForm(instance=Profile())
    return render(request, 'yourapp/register.html', {'form':form})